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搜题
【单选题】
下列说法错误的是A.
平面不是开区域.
B.
如果一个区域内任意两点之间的距离都不超过某一正数M，则该区域称为有界区域.
C.
包括边界在内的区域称为闭区域.
D.
不包括边界在内的区域称为开区域.
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参考解析：
知识点：
皮皮学刷刷变学霸
举一反三
【单选题】As a salesman, much of his success comes from being what his customers want.
A.
in competition with
B.
in contrast with
C.
in company with
D.
in tune with
【单选题】He ____ much of his success and happiness _____his wife and children.
A.
thanks; to
B.
owes; to
C.
owns; to
D.
thinks; highly of
【简答题】具有下列化学结构的药物是（ ）